Roast vs Body vs Acidity

Question

Coffee flavor is often described in terms of:

1. Roast darkness (light to dark)
2. Body (medium to heavy)
3. Acidity (smooth to bright)

I have a vague understanding of some of these, but am unclear especially on body. Could someone explain these a bit and show how they differ from one another?

Answer 1

I'm not really an expert, but in basic terms:

Roast darkness:

• Roughly how long was the coffee roasted, much like toast, a longer roast usually brings about a darker flavor. Darker roast coffees tend to have a slightly burnt caramelized flavor.

Body:

• I usually think of this as more of a texture than a flavor, probably more easily noticed at the extremes. A "full bodied" coffee sort of coats the tongue causing the flavor to linger while "medium bodied" coffees tend to be a little lighter with a cleaner finish.

Acidity:

• Acidity is basically what it sounds like, lower acid coffees are often referred to as "smooth" and higher acid coffees referred to as "bright".

Now as mentioned in the comments these terms are really painfully relative, and somewhat rendered meaningless by an onslaught of advertisers claiming that their coffee is "smooth dark and full-bodied" regardless of the real characteristics.

Answer 2

Body can sometimes also be described as "mouth feel". How "heavy" the coffee feels in ones mouth. Roast darkness varies, of course, with the roast level. However, body and acidity vary not only with roast level, but also with the variety of bean itself being roasted. Different varieties of coffee will have varying different levels of body and acidity, which is further affected by the roast level applied to the beans.

Answer 3

I think the terms are used quite loosely. For instance, the subjective “acidity” has little to do with the actual acidity in the brew. Out of interest, I measured the acidity of this morning’s espresso with pH paper. My tap water is pH 6.75 (very slightly acidic compared with neutral pH 7.0). The coffee was pH 6.5 . For comparison, table vinegar was completely off the scale blow pH 4.0 . Even when the vinegar was diluted 100:1 it was still below pH 4.0.

So coffee is less that 1/100th as acidic as table vinegar. I don’t think anyone’s taste buds are going to tell the difference in actual acidity between two cups of coffee.

When I taste my morning espresso, the things I focus on are

1. Body: does the coffee coat all parts of my tongue with flavor? ?
2. Bitterness: Does the coffee “bite” the side edges of my tongue? A bit of bite is OK.
3. Legs: How long does the taste last and how does the flavor develop during that period?

A great coffee offers flavor to your entire mouth and the flavor changes and develops for at least 30 seconds after a sip. A miserable coffee leaves you with no flavor after a few seconds… except a bitter bite on the edges of your tongue.